HIV (Human Immunodeficiency Virus) infection is associated with high rates of depressive symptomatology. There is evidence that such infection is associated with damage to the basal ganglia. It has also been suggested that the basal ganglia are implicated in the etiology of affective disorders. The study involves MRI and SPECT scans of subjects to examine structural and functional brain aspects of depression and dementia in AIDS. We examined the association between basal ganglia atrophy and depression in HIV seropositive men. We hypothesized that depressed HIV seropositive patients would have smaller basal ganglia compared with non-depressed HIV positive comparison subjects. Using quantitative magnetic resonance imaging (MRI) techniques, we compared the basal ganglia volumes of sixteen depressed, and sixteen group-matched nondepressed HIV seropositive homosexual men. We found no significant difference in basal ganglia volumes between the two groups. We suggest that depression, at least in the early stages of HIV infection, is not associated with basal ganglia atrophy.